1. Field of the Invention
The present invention relates to a wiring harness formed by combination of a plurality of sub-harnesses.
2. Description of the Related Art
A wiring harness for use in an automobile usually comprises a plurality of electric wires and connectors and has a complicatedly-branched geometry. Assembly of a wiring harness into a finished product through a single operation is not easy. Therefore, there is employed a series of manufacturing processes wherein a wiring harness is separated into a plurality of sub-harnesses of smaller blocks. After having been assembled individually, the sub-harnesses are connected into a completed wiring harness (see, for example, Japanese Patent Application Laid-Open No. 25781/1999).
The size of each block of sub-harness is determined in consideration of ease of assembly of sub-harnesses. For example, a wiring harness is separated into sub-harnesses such as those shown in FIG. 14. Sub-harnesses 101X and 101Y are assembled, by means of inserting terminal hardware pieces 104F connected to respective ends of electric wires 103 extending between a plurality of connectors 102A, 102B, 102C, 102D, and 102E. As a result of the wiring harness having been separated in the manner as mentioned above, the electric wires 103 must be connected to other sub-harnesses (not shown) disposed between the two sub-harnesses 101X and 101Y. Therefore, after-insert terminals 104R each having one end that is not connected to the connectors 102A through 102C are exposed outside the sub-harnesses 101X and 101Y so as to be inserted into other sub-harnesses in a subsequent bundling process.
As shown in FIG. 15, the sub-harness 101X is laid along wire holders 106 situated upright on a work table 105 for assembling and bundling the sub-harnesses 101X and 101Y. In this state, the after-insert terminals 104R to be inserted into the connectors 102D and 102E of the remaining sub-harness 101Y remain exposed. Subsequently, as shown in FIG. 16, the remaining sub-harness 101Y is laid along predetermined paths, and the after-insert terminals 104R of the sub-harness 101X are inserted into the corresponding connectors 102D and 102E, respectively. Similarly, the after-insert terminals 104R of the sub-harness 101xe2x80x2 are also inserted into the corresponding connectors 102A and 102B of the sub-harness 101X. Thus, the wiring harness is assembled.
Terminal hardware which is connected to the terminals of the electric wires 103 and is to be inserted into the connectors 102A through 102E includes a insulation displacement terminal 104a and a crimp terminal 104b. As shown in FIG. 17, the insulation displacement terminal 104a is constituted by means of press-fitting the electric wire 103 into pressure-connecting blades 107. As shown in FIG. 18, an insulating sheath 103a provided at the extremity of the electric wire 103 is stripped, thereby uncovering cores 103b. The thus-exposed cores 103b are crimped by means of a wire barrel 108, thereby constituting the crimp terminal 104b. 
In connection with the crimp terminal 104b, the cores 103b are strongly crimped by the wire barrel 108 by means of a press. Hence, there is yielded an advantage of superior reliability of electrical contact with the electric wire 103. Further, the crimp terminal 104b possesses high tensile strength and is less impervious to causing removal of the electric wire 103. However, processing pertaining to complicated processes, such as stripping of the electric wire 103 and crimping of the electric wire using a press machine, must be performed for each of the crimp terminals 104b (for each electric wire 103). Thus, the wiring harness becomes costly, thereby deteriorating manufacturing efficiency.
In connection with the insulation displacement terminal 104a, there is no necessity of stripping the electric wire 10 or press-fitting the electric wire 103 to the insulation displacement terminal 104a. The only requirement is to merely push the electric wire 103 into the pressure-connecting blades 107. By means of a single operation, a plurality of electric wires 103 can be pressure-connected to a plurality of insulation displacement terminals 104a aligned in line. Further, a process of inserting the insulation displacement terminal 104a crimped to the electric wire 103 into the connectors 102A through 102E can be automated. Hence, there is yielded an advantage of ability to efficiently manufacture sub-harnesses at lower cost.
In order to curtail manufacturing costs or improve manufacturing efficiency, all terminal hardware pieces, including the terminals 104F to be inserted into the connectors 102A through 102E and after-insertion terminals 104R which remain exposed and are not inserted into the connectors 102A through 102E when the sub-harnesses 101X and 101Y are not combined, are desirably formed from the insulation displacement terminals 104a. 
However, in relation to the insulation displacement terminal 104a, the electric wire 103 is merely press-fitted into the pressure-connecting blades 107. Hence, the electric wire 103 is readily removed from the insulation displacement terminal 104a. Further, press-fitting is inferior to crimping in terms of protection of a connection section (i.e., a pressure-connecting section) under external force. The after-insertion terminals 104R are transported or handled while temporarily being in an exposed state. Against such a backdrop, crimp terminals 104b, rather than insulation displacement terminals 104a, are more preferably employed as the after-insertion terminals 104R.
In relation to the electric wire 103 of the after-insertion terminal 104R, there is a conceivable method of connecting the insulation displacement terminals 104a to ends of the electric wires 103 to be inserted into the connectors 102A through 102E and connecting the crimp terminals 104b to the remaining ends of the electric wires 103 as the after-insertion terminals 104R. However, connecting two different connection types of terminal hardware pieces; that is, the insulation displacement terminal 104a involving press-fitting and the crimp terminal 104b involving crimping, to a single electric wire 103 results in considerable deterioration of manufacturing efficiency. Hence, such a method is desirably avoided.
Crimping is not applied solely to connection of the after-insertion terminal 104R. For instance, terminal hardware (see FIG. 19) to be connected to an electric wire of special form, such as a shield wire 103S having a shield layer 103Sa, and terminal hardware (see FIG. 20) which is to be used in an exposed form and not connected to a connector even when a wiring harness is completed (see FIG. 20), such as a ground terminal 104E, must employ crimping as a connecting method.
As mentioned above, in terms of cost, use of the insulation displacement terminals 104a is preferable at the time of manufacture of the sub-harnesses 101X and 101Y and a wiring harness. In spite of this, there has been a necessity of employing crimp terminals 104b for a portion of terminal hardware pieces. Further, difficulty is encountered in mixedly employing the crimp terminal 104b and the insulation displacement terminal 104a for each of the sub-harnesses 101X and 101Y. Hence, the majority of related-art sub-harnesses 101X and 101Y use only the crimp terminals 104b. The insulation displacement terminals 104a are used in only special portions of a sub-harness where there is no necessity of using the crimp terminals 104b. 
The present invention has been conceived against the foregoing backdrop and an object of the invention is to provide a wiring harness which enables effective heavy use of sub-harnesses using insulation displacement terminals.
To this end, the present invention provides a wire harness formed by combination of a plurality of sub-harnesses, comprising:
a sharable housing which enables insertion of crimp terminals formed by stripping extremities of electric wires and crimping resultantly exposed core wires to a wire barrel and insertion of a insulation displacement terminal formed by pressure-connecting each of electric wires between pressure-connecting blades;
a first insulation displacement sub-harness which has a plurality of housings including the shareable housing and is assembled by means of inserting the insulation displacement terminals pressure-connected to the electric wires into the housings;
a second crimp sub-harness assembled in the same manner as the first sub-harness; and
an after-insertion electric wire having the crimp terminals provided at respective ends, wherein the crimp terminal provided one end of the after-insertion electric wire is inserted into the sharable housing of the first sub-harness; the crimp terminal provided at the other end of the after-insertion electric wire is inserted into the sharable housing of the second sub-harness; and the first and second sub-harnesses are coupled together by way of the after-insertion electric wire.
The present invention also provides a wire harness formed by combination of a plurality of sub-harnesses, comprising:
a sharable housing which enables insertion of crimp terminals formed by stripping extremities of electric wires and crimping resultantly exposed core wires to a wire barrel and insertion of a insulation displacement terminal formed by pressure-connecting each of electric wires between pressure-connecting blades;
a first insulation displacement sub-harness which has a plurality of housings including the shareable housing and is assembled by means of inserting the insulation displacement terminals pressure-connected to the electric wires into the housings;
a second crimp sub-harness assembled by means of inserting the crimp terminal crimped to the electric wire into the housing; and
an after-insertion electric wire having the crimp terminals provided at respective ends, the crimp terminal provided at one end being inserted into the housing of the second sub-harness, and the crimp terminal provided at the other end remaining uninserted, wherein the crimp terminal provided at the other end of the after-insertion electric wire is inserted into the sharable housing of the first sub-harness, thereby connecting together the fist sub-harness and the second sub-harness by way of the after-insertion electric wire.
Preferably, the second sub-harness has a shield line having crimp terminals provided at both ends, the crimp terminals being inserted into the housing, and/or an earth line having at one end a crimp terminal inserted into the housing and at the other end an uninserted earth terminal. Preferably, the sharable housing has a retainer mount hole communicating to an exterior surface of the sharable housing from an inner wall of the cavity into which the crimp terminal or the insulation displacement terminal is inserted, and a retainer for preventing removal of the crimp terminal and/or the insulation displacement terminal attached to the retainer mount hole.
Preferably, a connection section is formed in each of the crimp terminal and the insulation displacement terminal so as to become identical in shape with a mating terminal; a step is formed in the crimp terminal so as to become identical in shape with the insulation displacement terminal; and a terminal engagement section is formed in the retainer for preventing removal of the crimp terminal and/or the insulation displacement terminal by means of engaging with the step.
There is employed, as a housing for interconnecting the first and second sub-harnesses, a sharable housing compatible with a crimp terminal and a insulation displacement terminal. Only terminal hardware to be connected to an after-insertion electric require which requires adhesion strength between an electric wire and terminal hardware is embodied as a crimp terminal. The majority of terminal hardware pieces which do not require adhesion strength are embodied as insulation displacement terminals. Thus, the present invention is advantageous in terms of cost and manufacturing efficiency.
The first insulation displacement sub-harness is provided with a sharable housing compatible with a crimp terminal and a insulation displacement terminal. A crimp terminal of the after-insertion electric wire of the second crimp sub-harness is inserted into the sharable housing. Thus, the insulation displacement sub-harness and the crimp sub-harness can be coupled together. Of the two sub-harnesses coupled together, a insulation displacement terminal is used for the first sub-harness. When compared with a case where all terminal hardware pieces are embodied as crimp terminals, the present invention is advantageous in terms of cost and manufacturing efficiency.
When either a crimp terminal or a insulation displacement terminal is embodied as terminal to be inserted into a cavity, the terminal hardware can be locked without fail.
The crimp terminal or the insulation displacement terminal inserted into the cavity is locked by means of engaging the step of the crimp terminal or insulation displacement terminal with the terminal engagement section.